Error when trying to enable flash cache

[CRD]

Good day

My client has received 8 * new SSD disks (ARFA1920S5xnNTRI) and it has been installed in their 3par 8200. System has all-inclusive license and firmware is up to date. Previously they only had FC disks.

When trying to enable flash cache I get this error, see screenshot

Any ideas to why this will happen?

[support_s]

System recommended content:

1. TMDS: EIO Ownership error when trying to Enable or Disable FLASH with TMDS

Please click on "Thumbs Up/Kudo" icon to give a "Kudo".

Thank you for being a HPE valuable community member.

[sbhat09 · Accepted solution]

Hello @CRD,

Please check if each of the SSDs have enough free space to dedicate for flashcache. You can run this command and check unused free chunklets - 'showpd -c -p -devtype SSD'
[Hope that must not be an issue because these SSDs are new and fairly large in size]

If free space is not a problem among SSDs, please try to create flashcache from CLI:
createflashcache 64g

Let me know if you need more assistance.

Regards,
Srinivas Bhat

If you feel this was helpful please click the KUDOS! thumb below!
Note: All of my comments are my own and are not any official representation of the company.

[CRD]

Hi Srinivas

Hope all is wel and thanks for the help, enabling flashcache from the cli worked, see screesnhots below.

Keep well

[CRD]

Just another thing, is it normal for the flashcache to show 100% used or is it rather an indication that assigning more flashcache space will be beneficial?

[sbhat09]

Hello @CRD,

Run the command showflashcache to ensure that the flashcache is all fine.

Yes. It is normal to show flashcache is 100% used. Flashcache space is different than rest of the SSD diskspace. Allocated flashcache space will be fully dedicated and doesn't show free space even if it is free.

Regards,
Srinivas Bhat

If you feel this was helpful please click the KUDOS! thumb below!
Note: All of my comments are my own and are not any official representation of the company.

[CRD]

Thanks Srinivas

Makes sense

If the client wants to increase flash cache to 128Gb for exampe in future would it just be the same cli command as you provided before for example

createflashcache 128g

Or is it different for the adjustment of a already enabled flashcache?

[sbhat09]

Hello @CRD,

To increase the flashcache, you need to remove the flashcache and create it again with the same command for 128gb - createflashcache 128g. This will not affect data and totally safe to remove and re-create for higher value.

I will provide the sequential commands for that shortly.

Regards,
Srinivas Bhat

If you feel this was helpful please click the KUDOS! thumb below!
Note: All of my comments are my own and are not any official representation of the company.

[sbhat09]

Hello @CRD,

Here is the procedure to change/increase flashcache:

Run the command showflashcache to capture the existing flashcache settings.
Then remove the flashcache with the command removeflashcache
(This will flush the flashcache data to drives and removes flashcache)
Then create the flashcache with the command createflashcache ***g
Again run the command showflashcache to ensure the flashcache is created as expected.
If the flashcache is created but not enabled, run this command: setflashcache enable sys:all

Regards,
Srinivas Bhat

If you feel this was helpful please click the KUDOS! thumb below!
Note: All of my comments are my own and are not any official representation of the company.

[CRD]

Thank you very much Srinivas, your help is much appreciated

Keep well